The Rising Influence of Rising Affluence

[OakesCS]

DOA,
regarding: Does compressed natural gas or liquid propane make sense as an automobile fuel in situations where oil refining capability is limited? ... Or, in another guise, is it easier and more economical to generate fuel grade CNG or LP than gasoline or diesel? .... This argument has been raised to justify an expectation that natural gas vehicles will be widely adopted in countries such as Iran that have inadequate refining capacity.

in cases where NG is available or cheaper to import than crude oil, diesel, or gasoline then CNG is a viable alternative. The premier example is Pakistan.
http://en.wikipedia.org/wiki/Compressed_natural_gas

However, you'll note that all of the countries that have a lot of CNG vehicles do NOT have an extensive trans-national (intrastate) transportation and commerce network, i.e. they tend to have a few big cities in which most of the country's population live and the CNG vehicles operate strictly within those cities. If those countries had significant crude oil resources, then i'm sure they would use that rather than NG. Brazil is a bad counter argument because until recently, their substantial crude oil resource was unknown and they have a semi-captive neighbor with lots of natural gas.

I wouldn't use Iran as an example for any process which involves logic. There's no reason why they couldn't have or operate refineries other than the incompetence of the yahoos running the country.

I don't think refining capacity or processing costs are the determining factor in whether to use NG for transportation fuels. NG reservoirs are much more geographically wide spread and it's easy and cheap to transport. Refined oil has a much higher energy density so it is the fuel of choice for transportation in most developed countries. However, if NG is cheaper and still practical then that's what people do.

In the US we had abundant oil reserves, we have an extensive and widely distributed ground commerce system, and many widely spaced cities. Consequently, refined petroleum became the entrenched transportation fuel. Building the network to displace the existing fuel infrastructure would be extremely expensive and i don't think running 18 wheel trucks on CNG would be practical. Of course, those sorts of things don't seem to be much of a barrier lately.

For short haul transportation (commuting) with regulatory restrictions on CO2 emissions and requirements for CO2 sequestration I suspect that it would make more sense to use NG and coal for centralized electrical power generation and switch to battery powered cars rather than CNG cars. Battery manufacturing might be just as expensive and emissions intensive as building a CNG distribution network for cars but I suspect that more of the cost would be born by industry (which i believe would be more effectively passed on than from govmint) in the former case and controlling emissions would be much more effective.

I also have my doubts about the safety of home CNG fueling but that's a different topic.
regards,
Charlie